Based on a quick look around several sites, I'm not sure if Fedora 8 has support for that particular sound card. Unless there is a specific reason you need to use Fedora 8, I think the easiest thing to do would be to install a newer version of Fedora or some other distro. Fedora is currently at version 11, with version 12 getting close. Fedora 8 is almost two years old. If that doesn't work, then we'll have to dig deeper.
Hope this is helpful!